Refusal to repay refund

I recently booked a stay at this resort and used my loyalty card for the discount. I overpaid for this booking and required a refund, which they confirmed via email I would get at check in . When I checked in they then informed me that at check out they would refund me. Then when check out came they requested me to complete a refund form with my credit card details, copy of my id etc. It has now been 3 weeks and still no refund. When I enquired they advised me that they cannot refund into my credit card account and required my cheque account details. Which I provided, however I have still NOT received my refund.